1. Field of the Invention
The present invention relates to a system for directing a moving object, and more particularly to a system for directing a moving object such as a mobile robot to a charging device.
2. Description of the Related Art
Typically, a robot developed for industrial purposes is being widely used to achieve factory automation, and collects data or information on behalf of a human being under an extreme situation, which is unbearable for the human being.
Recently, the above-mentioned robotics technologies have been used for space industries, and have been rapidly developed in various ways, resulting in the implementation of human-friendly household robots.
The human-friendly household mobile robot uses a battery to guarantee mobility at any place. If a voltage charged in the battery is equal to or less than a predetermined voltage, the human-friendly household mobile robot is programmed to automatically return to a charging device, such that the battery is re-charged.
In order to normally return the mobile robot to the charging device, there is a need for the mobile robot to recognize its own relative location with respect to the charging device.
A representative technique for returning the mobile robot to the charging device is a method for employing output data of an encoder mounted to a moving wheel. This technique has a disadvantage in that it cannot compensate for errors caused by a slip or no-load rotation of the wheel, such that it is considered to be an undesirable method.
FIG. 1 is a conceptual diagram illustrating a conventional system for estimating a relative location of a robot acting as a moving object.
Referring to FIG. 1, the system includes a plurality of Beacon modules 100 installed to many places of a room ceiling, such that it estimates a relative location of a mobile robot 200. Each Beacon module 100 includes an ultrasound transmitter and a Radio Frequency (RF) receiver.
If the mobile robot 200 equipped with an ultrasound receiver and an RF transmitter requests ultrasound generation from the Beacon module 100, the Beacon module 100 transmits an ultrasound signal to the mobile robot 200 upon receipt of the request. Therefore, the mobile robot 200 calculates an arrival time of the ultrasound signal emitted from each Beacon 100, such that it can calculate a distance from the mobile robot 200 to each Beacon 100. And, the mobile robot 200 estimates its relative location, such that it can return to the charging device.
However, the above-mentioned system for employing the Beacon has a disadvantage in that a plurality of Beacons must be installed to many places of a room ceiling, such that the costs of implementing the system are unavoidably increased due to the use of many Beacons.